Abstract
The resistance-temperature characteristics and self-heating of three ceramic-encapsulated rhodium-iron alloy resistance thermometers have been studied below 80K. The stability of the thermometers at 20K on repeated thermal cycling between 20 and 288K proved to be excellent (+or-25 mu Omega over 20 cycles). Small changes in resistance (up to 0.6 m Omega ) were noted on physical handling of the thermometers.